140 B. E. Fernow—The Battle of the Forest. 
are intermixed, and on certain soils, especially gravelly drifts 
and dry sand plains, as on the pine barrens of northern Michi- 
gan, they congregate even to the exclusion of other species. 
Instead, we can divide this deciduous-leaved forest by a line 
running somewhere below the fortieth degree of latitude, where 
with the northern limits of the southern magnolias and other 
species we may locate in general the northern limit of the south- 
ern forest flora. Northward from here, in what may be called 
the “ middle Atlantic forest,” the deciduous species rapidly de- 
crease and the coniferous growth predominates until we arrive 
at the broad belt of the northern forest, which, crossing from the 
Atlantic to the Pacific and composed of only eight hardy species, 
takes its stand against the frigid breath and icy hands of Boreas. 
Abounding in streams, lakes and swampy areas, the low 
divides of this region are occupied by an open stunted forest of 
black and white spruce, while the bottoms are held by the balsam 
fir, larch or tamarack, poplar, dwarf birch and willow. The 
white spruce, paper or canoe birch, balsam, poplar and aspen 
stretch their lines from the Atlantic to the Pacific over the whole 
continent. 
On the Pacific side the subdivisions are rather ranked from 
west to east. While the northern forest battles against the cold 
blasts from icy fields, the front of the Pacific interior forest is 
wrestling with the dry atmosphere of the plains and interior 
basin. Here on the driest parts, where the sage brush finds its 
home, the ponderous bull pine is the foremost fighter, and where 
even this hardy tree cannot succeed in the interior basin several 
species of red cedar hold the fort, in company with the nut pine, 
covering with an open growth the mesas and lower mountain 
slopes. Small and stunted, although of immense age, these 
valiant outposts show the marks of severe struggles for existence. 
On the higher and therefore moister and cooler elevations and 
in the narrow canyons, where evaporation is diminished and the 
soil is fresher, the somber Douglas, Engelmann and blue spruce 
and the silver-foliaged white fir join the pines or take their 
place. 
With few exceptions the same species, only of better develop- 
ment, are found in the second parallel, which occupies the 
western slopes of the Sierra Nevada. Additional forces here 
strengthen the ranks, the great sugar pine, two noble firs, a 
mighty larch, hemlocks and cedars vie with their leaders, the 
